In this paper, we study the correlation between the crystallinity of semiconductive compounds for eco-friendly power cables and the dispersive properties of carbon black. The crystal structure of the polymer material is advantageous for mechanical properties and heat-resistance. However, the polymer acts as an inhibitor to the dispersibility of carbon black. The purpose of this study is to develop a TPE semiconductive compound technology. The high heat resistance and ultra-smoothness characteristics which are required for high voltage and ultra-high voltage cables should be satisfied by designing and optimizing the structure of a non-crosslinking-type eco-friendly TPE semiconductive compound. The application of excess TPE resin was found to not only inhibit the processability in the compounding process, but also reduced the dispersion properties of carbon black due to higher crystallinity. After the crystallinity of the compound was identified through DSC analysis, it was compared with the related dispersion characteristics. Through this analysis and comparison, we designed the optimal structure of the eco-friendly TPE semiconductive compound.